Alert archive / New York / Severe Thunderstorm Watches in 2007

Severe Thunderstorm Watch 690

September 27, 20074 states

The Storm Prediction Center issued this severe thunderstorm watch at Sep 27, 2007, 1:49 PM EDT for 4 states. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Sep 27, 2007, 1:49 PM EDT (17:49 UTC)
Expired
Sep 27, 2007, 10:00 PM EDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 47 counties

Berkshire County, MA, Belknap County, NH, Carroll County, NH, Coos County, NH, Grafton County, NH, Merrimack County, NH, Sullivan County, NH, Albany County, NY, Broome County, NY, Chenango County, NY, Clinton County, NY, Columbia County, NY, Cortland County, NY, Delaware County, NY, Dutchess County, NY, Essex County, NY, Fulton County, NY, Greene County, NY, Hamilton County, NY, Herkimer County, NY, Madison County, NY, Montgomery County, NY, Oneida County, NY, Otsego County, NY, Rensselaer County, NY, Saratoga County, NY, Schenectady County, NY, Schoharie County, NY, Sullivan County, NY, Tioga County, NY, Ulster County, NY, Warren County, NY, Washington County, NY, Addison County, VT, Bennington County, VT, Caledonia County, VT, Chittenden County, VT, Essex County, VT, Franklin County, VT, Grand Isle County, VT, Lamoille County, VT, Orange County, VT, Orleans County, VT, Rutland County, VT, Washington County, VT, Windham County, VT, Windsor County, VT

The radar

The Burlington radar (KCXX), 90 km from the middle of the area, began a volume at 17:50 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
10%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

19 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Sep 27, 2:13 PM EDTSevere Thunderstorm WarningBTVEssex62 min
Sep 27, 2:20 PM EDTSevere Thunderstorm WarningBTVWindsor55 min
Sep 27, 2:50 PM EDTSevere Thunderstorm WarningGYXSullivan40 min
Sep 27, 2:52 PM EDTSevere Thunderstorm WarningGYXCoos38 min
Sep 27, 3:25 PM EDTSevere Thunderstorm WarningGYXMerrimack, Sullivan35 min
Sep 27, 3:39 PM EDTSevere Thunderstorm WarningBTVCaledonia, Essex66 min
Sep 27, 3:41 PM EDTSevere Thunderstorm WarningGYXBelknap, Grafton34 min
Sep 27, 4:01 PM EDTSevere Thunderstorm WarningGYXSullivan44 min
Sep 27, 4:15 PM EDTSevere Thunderstorm WarningGYXBelknap, Grafton45 min
Sep 27, 4:18 PM EDTSevere Thunderstorm WarningGYXCoos42 min
Sep 27, 4:19 PM EDTSevere Thunderstorm WarningALYSaratoga56 min
Sep 27, 4:26 PM EDTSevere Thunderstorm WarningBGMChenango, Cortland49 min
Sep 27, 4:43 PM EDTSevere Thunderstorm WarningGYXCarroll47 min
Sep 27, 4:57 PM EDTSevere Thunderstorm WarningGYXSullivan48 min
Sep 27, 5:14 PM EDTSevere Thunderstorm WarningBGMChenango46 min
Sep 27, 5:28 PM EDTSevere Thunderstorm WarningALYWarren30 min
Sep 27, 5:43 PM EDTSevere Thunderstorm WarningBTVEssex62 min
Sep 27, 6:02 PM EDTSevere Thunderstorm WarningBGMOtsego33 min
Sep 27, 7:27 PM EDTSevere Thunderstorm WarningBGMTioga63 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 5.8 hours before the alert went out and 121 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Albany, NY at 12:00Z on 2007-09-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 924 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Albany, NY at 12:00Z on 2007-09-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
924 J/kg
Mixed-layer CIN
-83 J/kg
Mixed-layer LCL
814 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
74 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.5

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 27, 12:43 PM EDTMesoscale DiscussionSPCBerkshire, Franklin2 hr
Sep 27, 7:01 PM EDTMesoscale DiscussionSPCBerkshire89 min

Nearby

Severe Thunderstorm Watches in New York, 2007Severe Thunderstorm Watches in Vermont, 2007Severe Thunderstorm Watches in New Hampshire, 2007Every severe thunderstorm watch in 2007

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.